Geron Corp., the company that was conducting the first U.S.-authorized trial of human embryonic stem cells, is ending the program to focus on its cancer drugs. The Menlo Park company will eliminate 66 full-time jobs, or 38 percent of its workforce, and take a cash charge of $5 million in the fourth quarter and $3 million in the first half of 2012, Geron said in a statement Monday. "In the current environment of capital scarcity and uncertain economic conditions, we intend to focus our resources" on developing cancer drugs, John Scarlett, Geron's CEO, said in the statement. "By narrowing our focus to the oncology therapeutic area, we anticipate having sufficient financial resources to reach these important near-term value inflection points for shareholders without the necessity of raising additional capital."